Water vaporizer unit

ABSTRACT

In an immersion-type water-vaporizer unit from which the vapor is ejected in a well-defined jet, a high efficiency is obtained by using a long narrow connection tube between the water reservoir in which the unit is immersed and the vaporizing space in the unit. The latter is surrounded by a double-walled vessel, the cavity of which is hermetically sealed. A partial vacuum may be provided in the cavity and the remaining gas may be inactive. The connection tube is positioned at an oblique angle with respect to the bottom portion of the vaporizing space and the greater part of the length of the tube is positioned inside of the vaporizing space. An electric heating element is provided within the vaporizing space to vaporize water therein. A thermostat located within the cavity in proximity to the heating element maintains the temperature of the heating element within a predetermined range.

United States Patent [72] lnventor Oskar Alfred Kreiberg Kalkovnsvej 8, 6100 lladerslev, Denmark [21] App1.No. 845,966 [22] Filed July30, 1969 [45] Patented Oct. 5, 1971 [32] Priority July31,1968 [33] Denmark [31] 3694/68 [54] WATER VAPORIZER UNIT 7 Claims, 1 Drawing Fig.

[52] U.S.Cl 219/273, 21/119,219/275,219/3l7,219/362 [51] Int.Cl F22bl/28, 1105b 3/00 [50] FieldofSearch ..219/271-276, 362,315,317;128/192;21/1l8,119

[56] References Cited UNlTED STATES PATENTS 620,086 2/1899 Casper 219/315 1,430,548 10/1922 l-logue 219/273 1,909,973 5/1933 Lewisetal. 219/272 2,014,836 9/1935 Cowan 219/275X 2,211,407 8/1940 Christensen 219/272 H547 M/sr/L47/0A/6 Primary ExaminerA. Bartis Att0rneyBeveridge & De Grandi ABSTRACT: In an immersion-type water-vaporizer unit from which the vapor is ejected in a well-defined jet, a high efficiency is obtained by using a long narrow connection tube between the water reservoir in which the unit is immersed and the vaporizing space in the unit. The latter is surrounded by a double-walled vessel, the cavity of which is hermetically sealed. A partial vacuum may be provided in the cavity and the remaining gas may be inactive. The connection tube is positioned at an oblique angle with respect to the bottom portion of the vaporizing space and the greater part of the length of the tube is positioned inside of the vaporizing space. An electric heating element is provided within the vaporizing space to vaporize water therein. A thermostat located within the cavity in proximity to the heating element maintains the temperature of the heating element within a predetermined range.

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INVENTOR game/ a ATTORNEY S WATER VAPORIZER UNIT The invention relates to an immersion-type water-vaporizer unit having a vaporizing space comprising an electric heater for vaporizing water, an outlet opening for the steam and a narrow connection tube connecting the vaporizing space with a water reservoir separated from the vaporizing space by means of a double wall.

in known water-Vaporizers having a vaporizing space of this type the outlet opening is very great and therefore the pressure in the vaporizing space during operation is substantially atmospheric pressure. Therefore no boiling water will be forced from the vaporizing space to the reservoir and as the double wall gives a rather good heat insulation it is possible to obtain a comparatively great efficiency with these known devices.

However, it is often desirable that the steam leaves the device in a well-defined jet having a given direction. This is obtained by making the outlet opening comparatively narrow in which case a superatmospheric pressure occurs in the vaporizing space. in known water-Vaporizers of the last mentioned type the vaporizing generally takes place in a pulsating or cyclical manner because at first a strong vaporizing takes place whereby the pressure in the vaporizing space rises and water and, as the case may be, also steam is forced to the water reservoir through the connecting opening which is constituted by a hole in a wall between the vaporizing space and the reservoir. Hereafter the vaporizing and thereby also the prasure in the vaporizing space decreases, which has the effeet that water will again flow to the vaporizing space through the connecting opening.

These known vaporizers have a comparatively low efficiency which to some extent is due to the fact that the water in the reservoir is gradually heated to a high temperature soley because of the pulsating manner of thevaporizing. Therefore, no heat insulation has been provided in these known devices.

By the present invention a vaporizing unit is aimed at in which the steam is sent out in a well-defined directional jet and which has nevertheless a high efficiency.

In order to obtain this the vaporizing unit according to the invention is characterized in that the connecting hole has a substantially greater length than the one necessary to establish connection between the vaporizing space and the water reservoir and that the size of the steam outlet opening is so adapted to the diameter and length of the connecting tube that during normal operation of the vaporizing unit no water flows from the vaporizing space to the water reservoir. The long narrow connecting tube acts as a brake on the pulsating or cyclical vaporizing process. When the vaporizing starts and the pressure rises in the vaporizing space a flowing of water from the vaporizing space to the reservoir may take place, it is true, and a flowing of water to the vaporizing space will also take place when the water is transformed to steam and leaves the vaporizing space. However, an equilibrium will soon be established whereby the water level in the vaporizing space will be a short distance below the water level in the reservoir corresponding to the overpressure in the vaporizing space. If a pulsation tends to occur only a small quantity of water will be pressed from the connecting tube to the reservoir and this water has not yet reached the boiling temperature of water. Therefore only a very small quantity of heat will be transferred to the reservoir.

However, the long narrow connecting tube would not in itself be sufficient to give a substantial increase of the efficiency if heat could still be transferred directly through the wall of the vaporizing space to the water reservoir, so as is the case in known devices producing a well-defined vapor jet. Therefore the measure of the long narrow tube has to be combined with the good heat insulation of the wall of vaporizing space obtained by the means of the hermetic sealing.

In the cavity of the double wall a thermostat may be placed. It serves to disconnect the heating element in the case where there is no more water in the vaporizing space and the temperature therefore rises strongly. By placing the thermostat in the hermetically sealed cavity of the double wall a reduction of the oxidization of the thermostate contacts and thereby an increase of their life is obtained.

The heating element may be surrounded by a tube and this tubemay extend into the cavity of the double wall. Hereby is avoided that water vapor and other harmful gasses are sucked into the heating element by the heating and cooling thereof.

An improved heat insulation and a further reduction of the oxidization of metal parts may be obtained by providing a partial vacuum in the cavity of the double wall. Finally the remaining gas in the cavity of the double wall may be an inactive gas whereby corrosion of the inner surfaces of the double wall as well as of metal parts arranged therein or being in connection with the cavity may be completely avoided.

The thermostat may be so designed that it disconnects the current to the heating element when the temperature is a certain number of degrees above the boiling point of water and again connects the heating element to the supply current when the temperature has fallen some degrees. When there is no more water in the vaporizing space and the temperature therefore abruptly rises strongly above the boiling point of water the thermostat will disconnect the heating element so that no harmful temperatures occur. When the temperature has thereafter fallen some degrees the thermostat will again supply current to the heating element, the temperature of which rises until the thermostat again disconnects etc. Consequently the temperature of the heating element and thereby also of the surroundings thereof, i.e. of the places where boiler scale is likely to deposit, will oscillate up and down for which reason the boiler scale will fly off. Thus an automatic descaling of the device is obtained. This embodiment has the further advantage over the known devices where a permanent interruption of the current occurs when there is no more water in the device. In this case a member is required which has to be operated from outside when the device after having been supplied with water is to be put in operation again and this member can only with difficulty be carried through the wall of the vessel in a hermetical way. Such an operating member is not necessary in the above mentioned embodiment of the device according to the invention. As a result of the effective heat insulation only a very small current consumption occurs during the connection and disconnection of the thermostat when there is no more water in the vaporizing space because the periods during which current is supplied to the heating element are much shorter than the periods during which no current is supplied.

ln the following part of the description the invention will be explained more in details with reference to the drawing showing a section of an embodiment of the vaporizer unit according to the invention.

The vaporizer unit shown is in a manner which is not indicated in details arranged in a water reservoir 1.

The immersion vaporizer unit comprises a double-walled vessel means comprised of an outer cup-shaped container part 2 and an inner cup-shaped container part 3 surrounding a vaporizing space 4 which via a long narrow tube 5 is in connection with the reservoir. The outer and inner vessel parts are connected to each other via a heat-resistant insulating material 6 whereby a heat bridge between the two vessel parts is avoided. With the same purpose the tube 5 may be carried through the vessel walls in a heat insulating manner. The vessel is closed by means of a lid 7 having an outlet stub 8 in which there is a narrow passage for the vapor. The lid may be tightened relative to the vessel by means of an O-ring 9 and may serve as a safety valve.

At the bottom of the vaporizing space 4 there is an electric heating element 10 which via leads 11 and 12 is connected to one part 13 of a plug-and-socket connection and to a thermo stat 14 respectively. The other part 15 of the plug-and-socket connection is via a cord in connection with a plug 16 and may furthermore have an indicator lamp 17 which is adapted to glow either as long as current is supplied to the heating element or as long as the current to the heating element is disconnected by the thermostat 14. The part 13 which is arranged in a hermetically tight manner in the wall of the vessel part 2 has a collar 18 in which a projection 19 on the part 15 fits. The collar 18 and the projection 19 may be tightened in relation to each other by means of an O-ring When the immersion vaporizer unit is placed in the reservoir 1 water will flow through the tube until the water levels are in the same height within and outside the unit. When current is supplied to the heating element and a vaporization starts in the vaporizing space 4 a superatmospheric pressure occurs which has the effect that vapor is ejected through the stub which is a narrow elongated outlet means 8 and that water flows through the tube 5 to the reservoir 1. The water level in the vaporizing space 4 now falls until an equilibrium is established by which the superatmospheric pressure in the space 4 corresponds to the difference between the water levels inside and outside the vaporizer unit and by which the amount of steam produced corresponds to the amount which escapes through the stub 8. The amount of water which is transformed into vapor is substituted by new water flowing from the reservoir through the tube 5 to the vaporizing space 4.

If for some reason a small pressure rise should occur in the space 4 a little water will be pressed through the tube 5 to the reservoir 1 but it will be water which was on its way through the tube 5 to the vaporizing space 4 and which had therefore not yet been heated to the boiling point of water. Even in this special case only a very small amount of heat will be transferred from the vaporizing space 4 to the reservoir 1. Neither will heat be transferred through the walls of the vessel from the vaporizing space 4 to the reservoir 1 because in the double wall there will be an air layer providing a good heat insulation. This heat-insulating property of the double wall may be further improved if in the cavity of the double wall a partial vacuum is provided. Furthermore the faces of the vessel parts 2 and 3 facing each other may be polished, silvered etc. to reduce heat radiation. The hermetically closed cavity of the double wall will give an effective protection against corrosion of the inner surfaces of the vessel as well as of parts e.g. the thermostat 14 arranged in the cavity. The heating element 10 comprises a tube and if this tube extends into the cavity of the double wall the said protection against corrosion will be extended to the heating element. With a view to eliminating completely the corrosion, the remaining gas in the cavity of the double wall may be an inactive gas.

The end of the tube 5 situated in the vaporizer unit may be surrounded by a bushing 20 made of a plastic material precluding the deposition of boiler scale. If desired, the whole tube 5 may be lined with such a material.

The thermostat 14 may be so designed that it disconnects the current to the heating element 10 when the temperature has risen to a certain number of degrees above the boiling point of water e.g. to ll0-ll5 C. and again supplies the heating element with current when the temperature thereafter has fallen some degrees. Thus the thermostat does not function until there is no more water in the vaporizing space 4 e.g. because the water level in the reservoir 1 is beneath the tube 5. When there is no more water in the vaporizing space 4 the temperature will oscillate between e.g. 105 and 115 C. the heating element being only supplied with current in short periods before the thermostat again interrupt the current. This oscillating temperature of the heating element which takes place at a temperature level which is not harmful has the effeet that boiler scale on the heating element and the surroundings comes off whereafter it may be shaken out of the vessel after the removal of the lid 7.

In the lid preferably made of a plastic material a depression 21 is provided in which a few drops of an air-cleaning or perfume-producing liquid may be poured.

The vaporizer unit which is primarily intended as an air humidifier for living rooms may, if so desired, be supplied with water from a water tank or directly from a water conduit, the supplying being regulated by means of a float mechanism or another type of level-regulating mechanism.

In addition to the above mentioned purpose the vaporizer unit according to the invention may also be used for other purposes e.g. as an inhalation device, and egg boiler or a water heater.

The tube 5 may have any cross section. This also applies to the vessel 2,3 which may e.g. have circular or polygonal cross section. Furthermore the vessel may be cylindrical as shown on the drawing or it may be e.g. conical.

The heating element 10 need not be arranged in the vaporizing space 4 as shown on the drawing. It may be embedded in the bottom of the vaporizing space or situated in a double bottom or it may be arranged in the cavity of the double wall.

The tube 5 which should be long and narrow need not project as far into the vaporizing space 4 as shown on the drawing. Instead it may project a longer distance outside the vessel. A part of the tube may be substituted by a hose.

As a consequence of the hermitical closing of the vessel 2,3 no damage will occur if the whole vaporizer unit e.g. during cleaning is immersed into water. As a consequence of the watertight plug-and-socket connection 13,15 no damage will occur even if the cord is not removed in this case.

The vessel parts 2 and 3 may be made from stainless steel but also other materials may be used.

While I have described and illustrated a preferred embodiment of my invention, I wish it to be understood that I do not intend to be restricted solely thereto, but that I do intend to cover all modifications thereof which would be apparent to one skilled in the art and which come within the spirit and scope of my invention.

lclaim: 1. A vaporizer unit for immersion in a water reservoir, comprising;

vessel means having side and bottom portions for accommodating water to be vaporized, I

heating means operatively associated with said vessel means for heating said accommodated water to produce water vapor,

a narrow, elongated outlet means for said water vapor associated with said vessel means, said outlet means having a cross-sectional area substantially smaller than the crosssectional area of said vessel means, said outlet means directing the water vapor out of said vessel means in a well-defined, directional jet, and narrow, straight, elongated connection tube extending from inside of said vessel means to outside of said vessel means for admitting water from said reservoir to said vessel means to be vaporized, said tube being positioned at an oblique angle with respect to said bottom portion of said vessel means with the end of the tube inside said vessel means being elevated with respect to the end of the tube outside of said vessel means, and with the greater part of the length of said tube being positioned inside of said vessel means.

2. The unit of claim 1 wherein said vessel means comprises a first cup-shaped container having side and bottom walls enclosing a water-vaporizing chamber, a second cup-shaped container having side and bottom walls spaced from and surrounding said walls of said first cup-shaped container, a cavity being defined between the spaced apart walls of said first and second cup-shaped containers and means for hermetically sealing the cavity between the walls of said first and second cup-shaped container.

3. The unit of claim 2 wherein said elongated connection tube has a length several times the space between the sidewalls of said first and second cup-shaped containers.

4. The unit of claim 2 wherein said vessel means further includes a top portion which connects the sidewalls of said first cup-shaped container, said narrow, elongated outlet means being located in said top portion.

5. The unit of claim 2 wherein a partial vacuum and an inert gas coexist in said cavity.

outside of said bottom wall of said first cup-shaped vessel so as to be both within said cavity and in proximity to said heating means, said thermostat being electrically connected to said heating means to maintain the temperature of said heating means within a predetermined range. 

1. A vaporizer unit for immersion in a water reservoir, comprising; vessel means having side and bottom portions for accommodating water to be vaporized, heating means operatively associated with said vessel means for heating said accommodated water to produce water vapor, a narrow, elongated outlet means for said water vapor associated with said vessel means, said outlet means having a crosssectional area substantially smaller than the cross-sectional area of said vessel means, said outlet means directing the water vapor out of said vessel means in a well-defined, directional jet, and a narrow, straight, elongated connection tube extending from inside of said vessel means to outside of said vessel means for admitting water from said reservoir to said vessel means to be vaporized, said tube being positioned at an oblique angle with respect to said bottom portion of said vessel means with the end of the tube inside said vessel means being elevated with respect to the end of the tube outside of said vessel means, and with the greater part of the length of said tube being positioned inside of said vessel means.
 2. The unit of claim 1 wherein said vessel means comprises a first cup-shaped container having side and bottom walls enclosing a water-vaporizing chamber, a second cup-shaped container having side and bottom walls spaced from and surrounding said walls of said first cup-shaped container, a cavity being defined between the spaced apart walls of said first and second cup-shaped containers and means for hermetically sealing the cavity between the walls of said first and second cup-shaped container.
 3. The unit of claim 2 wherein said elongated connection tube has a length several times the space between the sidewalls of said first and second cup-shaped containers.
 4. The unit of claim 2 wherein said vessel means further includes a top portion which connects the sidewalls of said first cup-shaped container, said narrow, elongated outlet means being located in said top portion.
 5. The unit of claim 2 wherein a partial vacuum and an inert gas coexist in said cavity.
 6. The unit of claim 5 wherein said heating means is located inside the bottom wall of said first cup-shaped container and partially extends through a sidewall of said first cup-shaped container so that a portion of said heating means is located in said cavity.
 7. The unit of claim 6 wherein a thermostat is located on the outside of said bottom wall of said first cup-shaped vessel so as to be both within said cavity and in proximity to said heating means, said thermostat being electrically connected to said heating means to maintain the temperature of said heating means within a predetermined range. 